Read some explanations about how and why the earth's crust is moving.
The first one is by Jacob Emery, from the Mariana Islands. The other is by Suna Ericcson from Iceland.
Dear Junior Science Team: This is what I understand: Heat makes it move
The core of the Earth is the source of heat that drives plate motion. Material in the mantle is heated by the energy in the Earth’s core. This heat causes convection currents in the mantle. Have you ever watched soup boil? Look at the illustration below. As the heat energy from the stove is transferred to the pot and then to the soup, the soup at the bottom of the pot gets hot. It expands, and the hot soup becomes less dense. The warm, less dense soup moves up and floats over the cooler, denser soup. Once it gets to the surface, the soup spreads out and begins to cool. As it cools, it becomes denser, and it sinks. A constant flow starts up as the cooler soup continues to sink and the warmer soup continues to rise. That flow is called convection current. This same process happens in the mantle of the Earth. The very hot inner core transfers heat to the mantle material. The mantle material expands and becomes less dense so it rises. When molten material reaches the crust, it spreads out and cools. As the mantle material spreads out under the crust, it carries the crust with it. Sort of like a conveyor belt carrying your groceries at the store. The cooler material now becomes less dense and sinks back to the bottom of the mantle layer [or wherever]. The heating and then cooling of the fluid mantle, changes in the density and the force of gravity combine to set the convection currents in motion within the Earth. Sincerely, Jacob Emery Dear Fellow Junior Science Team
My name is Suna and I live in Iceland. I live in a place where the magma from the mantle is oozing out of a crack in the crust and the crust is moving apart.
What happens if there is a crack in the crust?
As you would expect, something escapes. Someone described the creation of mountains like the white of an egg oozing out through a crack of a hard boiled egg. That is a pretty good illustration of what happens. As the magma (mantle material) rises, it pushes its way out of the cracks in the crust and pushes the crust apart to create a rift (a narrow opening). As magma builds up at this rift, it creates a ridge. A ridge is a long narrow band of hills or mountains. In fact, the longest mountain chain in the world was formed this way. The Mid-Atlantic Ridge is a chain of volcanic mountains that runs right down the middle of the Atlantic Ocean and from the North Pole to the South Pole. Most of this ridge is underwater, so many of these volcanic eruptions go unnoticed. However, there are a few places where the mountains rise above sea level. Iceland is one of those places. Along the ridge, the land is always changing. Volcanoes erupt, magma oozes through cracks to add more crust, and islands are surfacing. It’s an exciting place. Your pal, Suna Ericcson
Discuss the following questions in your science class.
1. Why do the plates of the crust move?
2. Suna described how magma escapes through cracks in the crust, and crust is added as a result. Do you think crust is always added the same way? Why do you think this?
3. Do you think all volcanoes erupt the same way? What makes you think that?
Modelling what happens in the Earth's Crust.
Read some explanations about how and why the earth's crust is moving.
The first one is by Jacob Emery, from the Mariana Islands. The other is by Suna Ericcson from Iceland.
Dear Junior Science Team: This is what I understand: Heat makes it move
Sincerely, Jacob Emery
Dear Fellow Junior Science Team
My name is Suna and I live in Iceland. I live in a place where the magma from the mantle is oozing out of a crack in the crust and the crust is moving apart.
What happens if there is a crack in the crust?
As you would expect, something escapes. Someone described the creation of mountains like the white of an egg oozing out through a crack of a hard boiled egg. That is a pretty good illustration of what happens. As the magma (mantle material) rises, it pushes its way out of the cracks in the crust and pushes the crust apart to create a rift (a narrow opening). As magma builds up at this rift, it creates a ridge. A ridge is a long narrow band of hills or mountains. In fact, the longest mountain chain in the world was formed this way. The Mid-Atlantic Ridge is a chain of volcanic mountains that runs right down the middle of the Atlantic Ocean and from the North Pole to the South Pole. Most of this ridge is underwater, so many of these volcanic eruptions go unnoticed. However, there are a few places where the mountains rise above sea level. Iceland is one of those places. Along the ridge, the land is always changing. Volcanoes erupt, magma oozes through cracks to add more crust, and islands are surfacing. It’s an exciting place. Your pal, Suna EriccsonDiscuss the following questions in your science class.
1. Why do the plates of the crust move?
2. Suna described how magma escapes through cracks in the crust, and crust is added as a result. Do you think crust is always added the same way? Why do you think this?
3. Do you think all volcanoes erupt the same way? What makes you think that?